1. Field of the Invention
The present invention relates generally to systems for photographically storing data, and more particularly, to an electrophotographic method and apparatus for imaging selected fractional areas within a photosensitive film sheet.
2. Description of the Prior Art
Stimulated by the costs incurred in storing the ever-increasing volume of documentary material which is presently being generated, considerable effort has been expended in the past in the design and development of various electrophotographic and other data storage and retrieval systems. Particular emphasis has been placed on the design of microphotographic systems which may be used to decrease the physical bulk of such stored materials without sacrificing file retrieval and/or copy reproduction capabilities. Systems of this type are rapidly becoming as necessary as the conventional office copier because of the exorbitant storage costs and space requirements being encountered in both Government and private offices, schools, hospitals and in virtually every business, large and small.
A great number of microfilm systems, of both the photographic and microxerographic type, have been developed in the past and are generally satisfactory for their intended purpose. However, the above systems typically exhibit one or more disadvantageous characteristics which have proven to be serious drawbacks under normal conditions of operation. For example, conventional microfilm systems are often large and expensive, are inconvenient and/or complex to operate, do not provide full capabilities of selective imaging of individual microfiche frames either sequentially or by random access, do not readily enable the imaging of additional material onto partially filled film sheets, and incorporate either overly simplified or extremely complicated processing techniques requiring excessive processing time and/or resulting in images of poor quality.